The present invention relates to a communication system with at least two different access systems, wherein a first access system is capable of handling a first number of communications between a mobile user equipment and the first access system, and wherein a second access system is capable of handling a second number of communications between the mobile user equipment and the second access system.
The invention further relates to methods for managing a communication system with at least two different access systems, wherein a first access system is capable of handling a first number of communications between a mobile user equipment and the first access system, and wherein a second access system is capable of handling a second number of communications between the mobile user equipment and the second access system.
The invention further relates to a mobile user equipment capable of communicating in a communication system with at least two different access systems, wherein a first access system is capable of handling a first number of communications between a mobile user equipment and the first access system, and wherein a second access system is capable of handling a second number of communications between the mobile user equipment and the second access system.
Communication systems such as cellular and/or satellite based telephone systems have developed significantly in operations world-wide.
An important example of a communication system with a first access system and a second access system is an implementation of so-called “islands” of a new access system within an already existing access system. However, the invention is not limited to implementations of a new access system within an already existing access system, but applies to any communication system with at least two different access systems. The invention also refers to a communication system that is equipped differently within different service areas, for example giving users within cities a higher service quality than in rural regions.
Future communication systems will allow mobile user equipments to perform a greater number of communications simultaneously. Examples of the communication include telephone calls, faxes, downloading of data or uploading of data (file transfer). However, the invention is not limited to these examples. According to the invention, communication is not limited to any special form of transfer, neither to information transfer with establishing a connection nor to connectionless information transfer. According to the invention, communication includes connections as well as connectionless transfer of information such as Short Messaging Service (SMS). Future wireless scenarios for wideband wireless multimedia services can comprise: interactive news delivery (voice, video, E-mail, graphics), interactive e-mail (text, graphics, video clips), interactive audio (CD-quality voice, video, graphics), video conferencing, web browsing, dynamic Internet-based games, downloading large files from intranets or position/location-dependent “push” info.
An object of the invention is to create a communication system with a first access system and a second access system, wherein at least one of the access systems allows the mobile user equipment to perform more than one communication, wherein a intersystem handover of communication between the first access system and the second access system is possible.
A shortcoming of the known system is that an intersystem handover between the first access system and the second access system is not possible.
A further object of the invention is a method for managing a communication system with at least two different access systems, wherein a first access system is capable of handling a first number of communications between a mobile user equipment and the first access system and wherein a second access system is capable of handling a second number of communications between the mobile user equipment and the second access system. The method is carried out in a way that it is evaluated if a intersystem handover from the first access system to the second access system should be effected and if the intersystem handover is necessary maximally the second number of communications are handed over.
A further object of the invention is a method for managing a communication system with at least two different access systems, wherein a first access system is capable of handling a first number of communications between a mobile user equipment and the first access system and wherein a second access system is capable of handling a second number of communications between the mobile user equipment and the second access system. The method is carried out in a way that at least one of the communications is put on hold before the intersystem handover and kept on hold after the intersystem handover.
A further object of the invention is to provide a mobile user equipment, capable of communicating in a communication system with at least two different access systems. According to the invention, the mobile user equipment contains an indicator to indicate an intersystem handover to a mobile user.
Further advantageous embodiments and implementations are achieved according to the claims 2 to 14 and 16 to 37.
The invention makes use of the idea to distinguish between different communications and/or different types of communication. Thus the invention allows the communication system and/or the mobile user equipment to handover different communications and/or different types of communication in a different manner.
According to the invention, the problem is solved by a communication system with at least two different access systems, wherein a first access system is capable of handling a first number of communications between a mobile user equipment and the first access system and wherein a second access system is capable of handling a second number of communications between the mobile user equipment and the second access system. This is characterised in that the mobile user equipment and/or the communication system contains at least one means for making at least one decision which is capable of deciding which communications are handed over in the case that the mobile user equipment moves between the first access system and the second access system and in that the mobile user equipment and/or the communication system contain at least one means for executing the at least one decision.
The communication system allows mobile user equipments to communicate. A communication system consists of one access system. An access system consists of at least one access network and at least one core network. An access network consists at least of entities that manage the resources of the access network and provide the user with at least one mechanism to access the core network.
A core network consists at least of entities that provide support for the network features and telecommunication services. The support provided may include for example functionality such as the management of user location information, the control of network features and services, the transfer mechanisms for signalling and for user generated information.
An intersystem handover is a handover between a first and a second access system, or a handover within a first access system, in both cases between means with different capabilities.
As the invention is not limited to communication systems with UMTS and/or GSM as access systems, neither the access network nor the core network are limited to elements of UMTS implementations or GSM implementations. Each of the access systems may comprise at least one access network and at least one core network. As the invention relates to access systems with different capabilities of handling simultaneous communications, no special structure of the networks is required. Therefore the access network may be any installation, which is capable of giving mobile user equipments a capability of transferring information. The core network could be any installation, which is capable of transferring information to and/or from other communication systems, for example, a fixed network such as an Integrated Service Digital Network (ISDN), a Public Switched Telephone Network (PSTN) or a further mobile network.
As the invention relates to a large variety of communication systems, the nature and occasion of the means for making at least one decision which communication or communications are handed over in the case that the mobile user equipment would move between the first access system and the second access system, may vary too.
The means for making at least one decision may decide on the number and/or the identity of a communication or communications to be handed over. This includes also the case that no communication is handed over, for example when a mobile user decides not to continue a route in order to avoid a intersystem handover.
The mobile user equipment is capable of handing over at least one communication from the first access system to the second access system. Each of the access systems is capable of handling a certain number of communications for each of the mobile user equipments. A limitation of the number of communications originates for example in technical constraints as found in the conventional GSM system, which is capable of handling only one communication for the mobile user equipment. However, even systems which would principally allow a higher number of simultaneous communications for each of the mobile user equipments could be limited permanently or temporarily to a certain number of communications for each of the mobile user equipments.
Whereas an intersystem handover between an access system, that allows a lower number of simultaneous communications to an access system, which allows a higher number of simultaneous communications does not evoke problems, the intersystem handover in opposite directions is difficult.
The invention allows a management of different communications of a mobile user equipment which passes from a first access system with at least two, preferably more simultaneous communications to another access system allowing a lower number of simultaneous communications for each of the mobile user equipments.
The first access system comprises for example a Universal Mobile Telecommunication System (UMTS) and the second access system is a Global System for Mobile Telecommunication (GSM), or an Universal Mobile Telecommunication System (UMTS) which allows a lower number of simultaneous communications than the first access system.
The mobile user equipment is, for example, a mobile computer capable of communicating, a mobile telephone or a mobile multimedia system.
In an advantageous implementation of the communication system, the methods, and the mobile user equipment, the communication system contains at least one means for determining a capability of at least one of the access systems.
In a preferred embodiment of the communication system, the methods, and the mobile user equipment, the means for determining the capability is located in a core network.
In an advantageous implementation of the communication system, the methods, and the mobile user equipment, at least one access network of the communication system contains the means for executing the at least one decision.
In a preferred embodiment of the communication system, the methods, and the mobile user equipment, a core network contains the means for executing the at least one decision.
In a further advantageous implementation of the communication system, the methods, and the mobile user equipment, the mobile user equipment contains the means for executing the at least one decision.
In a preferred embodiment of the communication system, the methods, and the mobile user equipment, at least one access network of the communication system contains the means for making at least one decision.
In a further advantageous implementation of the communication system, the methods, and the mobile user equipment, a core network contains the means for making at least one decision.
In a preferred embodiment of the communication system, the methods, and the mobile user equipment, the mobile user equipment contains the means for making at least one decision.
In a preferred embodiment of the communication system, the methods, and the mobile user equipment, the communication system contains a means for making at least one decision whether an intersystem handover is necessary.
In an advantageous implementation of the communication system, the methods, and the mobile user equipment, the means for making at least one decision whether an intersystem handover is necessary is a device (DPH).
In a further advantageous implementation of the communication system, the methods, and the mobile user equipment, the device (DPH) is located in an access network (AN).
In an advantageous implementation of the communication system, the methods, and the mobile user equipment, the device is located in a radio network controller.
In a further advantageous implementation of the communication system, the methods, and the mobile user equipment, the device is located in a core network (CN).
In an advantageous implementation of the communication system, the methods, and the mobile user equipment, a Base Station Controller (BSC) and one or more Base Transceiver Stations (BTS) constitute an access network of the communication system. Within an implementation of a Global System for Mobile Communication (GSM) every mobile user equipment is linked to one Base Transceiver Station (BTS). In other access systems like implementations of a Universal Mobile Telecommunication System (UMTS) each of the mobile user equipments may be in a contact with more than one Base Transceiver Station (BTS).
In a preferred embodiment of the communication system, the methods, and the mobile user equipment, it is evaluated if an intersystem handover from the first access system to the second access system should be effected, wherein in the case that the intersystem handover is necessary at least one communication can be handed over.
In an advantageous implementation of the communication system, the methods, and the mobile user equipment, an access network sends an intersystem handover query to the mobile user equipment.
In a preferred embodiment of the communication system, the methods, and the mobile user equipment, the access network signals a core network before the access network sends the intersystem handover query to the mobile user equipment.
In a further advantageous implementation of the communication system, the methods, and the mobile user equipment, the core network adds information about a communication or communications that can be supported.
This information is based on a capability of at least one of the access systems, especially the capability of the access system to which the communication or communications are handed over.
In an advantageous implementation of the communication system, the methods, and the mobile user equipment, a mobile user decides about the communication or the communications which should be handed over to the second access system.
This decision can be taken at any suitable time, for example, in a setup message of the communication or after a signal that an intersystem handover is necessary.
In a preferred embodiment of the communication system, the methods, and the mobile user equipment, the mobile user equipment informs the access network about the communication or the communications which should be handed over to the second access system.
In an advantageous implementation of the communication system, the methods, and the mobile user equipment, the mobile user equipment informs the access network about the communication or the communications which should be handed over to the second access system at a communication setup.
In a preferred embodiment of the communication system, the methods, and the mobile user equipment, the mobile user equipment receives an intersystem handover query for intersystem handover towards the second access system and afterwards the mobile user equipment disconnects all connections, that cannot be kept in the second access system.
In a further advantageous implementation of the communication system, the methods, and the mobile user equipment, the core network decides which communication or communications should be handed over to the second access system.
The decision which communication or communications should be handed over to the second access system includes the case that no communication is handed over. An intersystem handover can be rejected by the access system, the mobile user equipment or the mobile user. The mobile user, for example, may decide to remain within a service area which is covered by the first access system.
In an advantageous implementation of the communication system, the methods, and the mobile user equipment, the mobile user equipment contains an information interface, for example an indicator either visual, audio and/or tactile example given a blinking light, to inform the mobile user about a potential intersystem handover. Therefore the mobile user can avoid an intersystem handover by stopping a movement out of the service area which is covered by the first access system.
In a preferred embodiment of the communication system, the methods, and the mobile user equipment,
the core network disconnects all calls which cannot be kept in the second access system.
In an advantageous implementation of the communication system, the methods, and the mobile user equipment, at least one decision about a communication or communications which are handed over in the case that the mobile user equipment (NUE) would move between the first access system and the second access system depends on at least one presetting.
In a preferred embodiment of the communication system, the methods, and the mobile user equipment, the presettings are located within a mobile user equipment.
In an advantageous implementation of the communication system, the methods, and the mobile user equipment, the presettings are transferred to the core network within an initial user equipment (IUE) message and/or in a setup message.
An initial user equipment (IUE) message is a message sent, before and independent of a setup message, containing at least information about presettings for an intersystem handover.
In a further advantageous implementation of the communication system, the methods, and the mobile user equipment, a message which depends on the presettings is sent to the core network after the core network has sent a request to the mobile user equipment.
In a preferred embodiment of the communication system, the methods, and the mobile user equipment, the message depends only on the presettings.
In an advantageous implementation of the communication system, the methods, and the mobile user equipment, the message depends also on an active decision of a mobile user.
In a further advantageous implementation of the communication system, the methods, and the mobile user equipment, the presettings are stored within an access network and/or an core network.
In a preferred embodiment of the communication system, the methods, and the mobile user equipment, the presettings can be different for different mobile users.
In an advantageous implementation of the communication system, the methods, and the mobile user equipment, the presettings are identical for all users.
In a preferred embodiment of the communication system, the methods, and the mobile user equipment, the presettings can be different for different categories of communications. Examples for different categories of communications are speech or data calls.
In an advantageous implementation of the communication system, the methods, and the mobile user equipment, the presettings can be different for different priorities.
An example for a priority call is emergency calls.
In a preferred embodiment of the communication system, the methods, and the mobile user equipment, the presettings are defined and/or modified by an operator.
In an advantageous implementation of the communication system, the methods, and the mobile user equipment, the presettings are defined and/or modified by a mobile user.
In a further advantageous implementation of the communication system, the methods, and the mobile user equipment, at least one of the communications is put on hold before the intersystem handover and kept on hold after the intersystem handover.
The invention also solves the problem to hand over multi-party calls. If one or more communication is put on hold, it is possible to reactivate the communication at a later time. However, the method of putting at least one communication on hold before the intersystem handover, to keep it on hold after the intersystem handover and to reactivate the communication at a later moment also applies to other communications as data communications. For example, if a mobile user equipment with an activated speech call and an activated down load of a file moves towards an access system which allows only one simultaneous communication, the data communication is put on hold and reactivated later, especially after the mobile user equipment has finished the speech call or has once again moved towards a third access system which allows more than one simultaneous communication.
In a preferred embodiment of the communication system, the methods, and the mobile user equipment, the mobile user equipment (MUE) puts the communication on hold.
In a further advantageous implementation of the communication system, the methods, and the mobile user equipment, the core network (CN) puts the communication on hold.
In a preferred embodiment of the communication system, the methods, and the mobile user equipment, a mobile user is informed before the intersystem handover. This allows a decision of the mobile user about a communication or communications he would like to maintain.